The invention relates generally to a lock and, more particularly, to a lock with a laterally-outwardly movable bolt that is supported in a housing and can be fixed in the locked position when a push-button mechanism actuated perpendicular to the plane of the housing is arrested in a securing position, and released from the locked position when the push-button mechanism is pushed beyond the securing position.
Such a push button actuated lock is known from German Patent No. DE3504806 C2. With this known lock a bolt that is movably supported in a housing slides laterally out of the lock housing, that is, it is brought into the locked position in parallel with the associated door in the mounted state, when a push button is pushed in perpendicular to the plane of movement of the bolt against a spring force, until it is arrested in a securing position. In this state the bolt can not slide back. To unlock it, the push button is released from the arrested state by depressing the push button beyond the securing position, thereby pulling the bolt back into the lock housing. The door is thus only secured when in the bolted position.
It is an object of this invention to provide a push button lock that overcomes some of the problems and shortcomings of devices of the prior art.
Another object of this invention is to provide a lock of the type indicated in the introduction that provides more security through the use of simple construction.
How these and other objects are accomplished will become apparent from the following descriptions and from the drawings.
The invention involves an improvement to a cabinet door lock having a laterally-outwardly movable bolt that is supported in a housing that defines a reference plane. The movable bolt is capable of being secured in a locked position when a push-button member, which is actuated by movement perpendicular to the reference plane, is in a securing position and released from the locked position when the push-button member is in a position beyond the securing position.
The improvement includes a compression spring biasing the movable bolt toward an extended position thereby allowing it to slide back into the housing having spaced parallel walls when a depressing force is applied to the bolt. The movable bolt has a pair of lateral members positioned along the inner walls and extending parallel to the direction of movement of the movable bolt. The lateral members have inner sides, each of which has a stop member thereon. The stop members have an abutment surface substantially perpendicular to the movement of the movable bolt, and the push-button member includes stop pins positioned for engagement with the abutment surfaces, whereby the movable bolt is prevented from sliding back farther into the housing when the push-button member is in the securing position.
According to the invention, it is provided that the movable bolt, when in the unlocked state, is biased in an extended position by means of a compression spring, but is held such that it can be slid back into the lock housing against the force of the spring, and that the movable bolt features an obliquity or roundness that acts together with a stop body, or is supported so as to swivel back. As a result of the bias resulting from the compression spring the movable bolt is also held in the extended state, that is in the extended position in the unlocked state, but can be moved back into the housing against the force of the compression spring when an appropriate traction force is exerted on the door. As a result of the obliquity or the roundness or the swiveling support, the movable bolt is moved into the housing by acting together with the counter surface on the body stop. The door can thus not swing open unintentionally when in the unbolted state. The reliability of operation is thereby increased according to the invention, in that the movable bolt features a stop member that blocks the movable bolt from sliding in when in the secured state, and that the stop member is released when the push-button member is depressed beyond the securing position.
In one embodiment of the invention, the movable bolt has an oblique-shaped front side, an oblique-shaped body stop is positioned in the cabinet so as to contact the oblique-shaped front side of the movable bolt, and the movable bolt is capable of sliding back into the housing when a traction force is exerted on the cabinet door. In a specific version of such embodiment, the front side of the movable bolt and the body stop are rounded.
According to the invention, the movable bolt, when in the unlocked state, is biased in an extended position by means of a compression spring, but is held such that it can be slid back into the lock housing against the force of the spring. In one embodiment of the invention, the movable bolt features an obliquity or roundness that acts together with a stop body. In another embodiment, the movable bolt is supported so as to swivel back.
As a result of the bias resulting from the compression spring the movable bolt is held in the extended state, that is, in the extended position in the unlocked state, but can be moved back into the housing against the force of the compression spring when an appropriate traction force is exerted on the door. As a result of the obliquity or the roundness or the swiveling support, the movable bolt is moved into the housing by acting together with the counter surface on the body stop thereby preventing the door from swinging open unintentionally when in the unbolted state. By appropriately arranging the body stop and the movable bolt, the door can be held in close contact with the body, so that annoying vibrating noises are avoided.
The invention increases the reliability of operation of the lock in that the movable bolt features a stop member that (1) blocks the bolt from sliding in when the push-button member is in the securing position, and (2) is released when the push-button member is depressed beyond the securing position.
If for some reason, the push-button member should be unintentionally moved during locking, the movable bolt will still remain freely movable. In this way, for example, a flap on which the lock is fastened can also be closed when the push button member is pushed in.
The construction of the lock is simple in an embodiment whereby the compression spring is arranged between a middle section of the back side of the movable bolt and the front side of a spring support platform that is fixed to the housing.
In addition to simple, compact construction, the features are further instrumental in that the movable bolt is guided along the inner walls of the lock housing by means of two lateral members. Guide paths that are oblique or curved from the housing cover are formed on the inner sides of the lateral members. It is these guide paths that the stop pins engage, with the result that, with the push-button member in the securing position, the movable bolt is blocked by the stop members against being pushed back in the housing, and the lateral members are guided past both sides of the spring support platform that is fixed to the housing.
In yet another embodiment of the invention, the compression spring is designed as a conical helical spring, and the back side of the bolt and the front side of the spring support platform feature recesses to which the respective facing end side of the compression spring is adapted. Such embodiment results in minimal block length for the spring thus allowing the assembly space for the compression spring to be designed with minimum dimensions.
The lock is easily constructed with a pin formed onto the floor of the lock housing and projecting into the inside of the housing. Inserted onto the pin is a screw shaped push button spring that elastically supports the push-button member in the direction of the housing floor. This allows the push-button member to be essentially guided out of the lock housing when in the unbolted state. The push-button member features a cross-shaped projection on the side opposite the rear side of the movable bolt. Such projection allows the push-button member to be guided in a cross-shaped guide groove that runs parallel to pin in the direction of movement of the push-button member. A tumbler with a gating mechanism is provided in a rear chamber of the lock housing, in which the free end of the cross-shaped projection that is directed away from the push-button member is set to the securing position when the push-button member is pressed, and out of which the cross-shaped projection can be released when the push-button member is pressed beyond the securing position.
The serviceability of the lock can be improved in that an ancillary spring is provided in addition to the push-button spring in order to support the push-button member in the extended state. Said ancillary spring is active in the initial phase of the inward movement of the push-button member, and is dimensioned such that when acting together with the push-button spring the need to push in the push-button member can be avoided, while the movable bolt is pushed into the lock housing against the force of the compression spring. The additional spring can be formed of bars which are part of the housing. Such bars can be swung out by means of nubs arranged on the push-button member.